Casting of ingots



ov '24, 1959 R. E. KRAMIG, JR 2,913,785

CASTING OF INGOTS Filed June ll. 1953 ATTORNEYS.

Kramig ut'ix and trustee `of the estate of said Robert E: Kramig, Jr.,deceased i i I r Application {une 11, 1953, Serial No.,;361,016v a 3 4`ca{ims. (o. 22 139 v This invention relates to the casting of ingots ofsteel, iron and other metals. The invention is addressed particularly tothe problem 'of preventing the adherence of an ingot castingtothesstoolupon which the ingot mold is mounted, and to prevent deterioratin ofthe-stool by the molten metal during casting.: i i i The present'invention is directed particularly` to an improvement` in :theutilization of the invention which is shown in Robert E. Kramig, Jr.,United States applica-` tion Serial No. 355,880,` filedzMay `18,` 1953,for "smirch Plate for'Ingot Moldsf' That application` discloses `amethod of casting ingots `in which a layer or sheet or plate of resinouslaminaterof densely compacted asbestos fibers is interposed between theupper surface 'of an ingot r stool and the lower surface of ;an ingotmold which is normally rested directly upon the stool. As disclosed in ifull area-at the bottom of placed 'upon' the stool in such position thatedgewise or 4 Z,9l3,785 Patented` Nov. 24, 1959 an ingot mold, but whichis of sufiicient dimension, either -lengthwisely or widthwisely or alonga diagonal line, to extend over the face of the stool and .presenteither edgewise or corner portions which-may be positioned beneath thestool so as to be held down thereby at those points. In conjunction withthis afra'ngement, the invention preferably contemplates the utilizationof a stool having a recess or cavity in its u`pper surface within whichthe smirch plate may be laid, the depth of the recess or cavity beingsuch in relation to the thickness of thesmirch plate that the surface ofthe latter is flush or substantially flush with the surface of theformer. In preparation for casting, therefore, a smirch plate of' thesize indicated is laid in the cavity of the stool whichis adapted toreceive it, then the mold is cornerwie= portions of'the plate arestraddled respectively by'portions of the ingot mold, in order that theingot mold may hold the smirch plate firmly in place against dislodgmentor lifting by the molten metal being i poured.

the aforesaid 'application, it has been discovered that a" smirch plate;of thisrnature is `capable' ofwithstanding the direct heat of themolten steel or iron which ispoured into the ingot mold, at least for aperiod of time sufricient to prevent the formation of a crater in .the`upper ingot to the metal of the stool.

In normal ingot founding, the molten metal is poured from a ladledirectly into the ingot mold, the stream falling through a distance ofsix to ten feet, at least at the start of the pourwhentheingotmold'isempty. Also, the stream is of substantial-size;forexarnple,"an ingot weighing anywhere from six to -ten' ton's"wil1 be`poured completely in a matter of approximatelythirty-*to sixty seconds.``It is apparent that these'cohditins createconsiderable turbulence ofmolten metal: within the ingot mold, particularly at the time oftheinitial impactof the falling stream of steel and driiig' the period whenit is only partially filled.

When the smirch plate extends facially over the entire bottom area ofthe ingot mold, with its edges held down against the stool under theweight of the ingot mold itself, no dislodgment of the plate can occurby the metal which is being poured. However, a smirch plate of the typedisclosed in the aforesaid patent application serves its greatestfunction at the start of the pour to prevent direct impact engagement ofthe hot molten metal against the metal of the stool, and this actionoccurs over a relatively localized target area rather than over theentire bottom area of the mold. Since a plate of resin laminate ofdensely compacted asbestos fibers is inherently a relatively expensiveproduct to produce, in terms of square foot cost, the objective of thisinvention has been to provide means for the utilization of a smirchplate which is less in size than the entire cross sectional area of thebottom of the mold, but which may be used efiectively to protect thestool against the cratering action which would otherwise attend theonrush of the poured stream of molten metal, and which will also beefiective to prevent seizure or bonding of the ingot to the metal of thestool.

The present invention, brefiy, contemplates the utilization of a smirchplate which is less in facial area than the surface of the stool and toprevent seizure of .the cast,

to he-e mployed. For example, smirch plates of resin- 'Thedrawingsjillustrate a typical embodiment of the present invention, inwhich;

Figure lis a top plan view looking down at an ingot mold which istesting upon the upper surface of a stool which is' equipped with asmirch plate in accordance with the -present invention, and I 'FigureZisa cross` sectional elevation taken on the line 2-2 of Figire l.

KIn the drawings, the stool is indicated generally at 1, the ingot moldat 2, both` of these elements being of `conventional size as will'bereadily understood by those skilled in the art. The' stool, However, atits upper surface'3, is` provided with a cavity or recess 4, and asmirch plate 5 is laid within this cavity beneath the ingot mold. Thesmirch plate, as will be noted, is less in facial area than the openingat the mold within the bottom thereof, but the plate is so dirnensioned,in the embodime'nt showm that the dimensional on the plate diagonal isgreater than the insidewidth of the mold at the bottom,

i so that 'corner portions 6--6 of the smirch plate may be straddled'byopposte edges of the mold when it is rested upon the stool. p

l he: recess 4 within the stool is dimensioned in conformity with thethickness of the smirch plate that is bonded asb estos laminatapproximately of an inch thickmay be used, in which event the cavity isof substantially the same depth. The cavity 4 may be produced within theupper surface of the stool in the casting thereof, and, therefore, itpermits the use of successive smirch plates of standard size in thesuccessive casting of ingots on the stool.

Diagonal disposition of the smirch plate is shown in the drawings as apreferred embodiment because the least area of smirch plate is requiredin such an arrangement to produce satisfactory results. It is to beunderstood, however, that a square or oblong smirch plate may beutilized within a corresponding stool cavity for disposition underneaththe mold in a direction transversely or longitudinally thereof. Suchvariations are not illustrated in the drawings because they are believedto be obvious modifications.

A'smirch plate upon which an ingot has been poured is substantiallydeteriorated by the molten metal and is not, therefore, convenientlyreusable in the founding of a successive ingot. However, in thearrangement provided by the present invention, the amount of smirchplate material which is required is substantially reduced over whatwould be required for disposition over the entire bottom area of theingot mold, and the cost, therefore, is substantially reduced. s

It will be noted that the surface areas of the stool between the insideedges of the ingot mold and the outer edges of the smirch plate areexposed directly to molten metal. However, if the stream of molten metalis targeted against the smirch plate, then these exposed metal surfaces'of the stool do not become cratered or seize to the ingot despite theirdirect engagement therewith; this result is probably obtained becausethe chilling efiect-of the stool metal is adequate to prevent adhesionor welding at areas outside the pouring stream of metal but would not beadequate at the direct point of impact of the stream with the stool.

In previous practice, when an ingot was cast upon a stool that had acrater already formed within it, the ingot, even if not stuck to thestool, would have upon its end a bulge of metal corresponding to thecrater shape, and this would have to be removed at considerable laborcost and with waste of metal. In the practice of the present invention,as in the practice of the inveution dis- 'closed in the aforesaidapplication, an ingot is produced having a substantially smooth, evenend which requires no attention prior to its use in the fabrication ofshapes' or sheets;

Having described my invention', I claim:

l. Apparatus for use in the casting of ingots comprising a` stoolhavinga substantially flat upper surface and an ingot mold having asubstantially fiat, open bottom adapted to rest upon the upper surfaceof said stool so that the stool constitutes a closure for the bottomofthe mold, the said stool having a recess in its upper surface which isless in area than the open area of the) bottom of said mold,'but whichhas a greater dimension,

in at least one direction, than the dimension of' the mold.

in respectively the same direction, whereby the mold may be placed' uponthe stool in position straddling the recess, r and a resinous laminate'of densely compacted asbestosv` fibers occupying substantially theentire area of said* recess and having' its upper surface substantiallyflush with the surface of said stool, the said' resinous laminateconstituting a targetagainst which molten metal may be poured into saidmold, to prevent cratering of the stool or seizure of the cast metalthereto.

2. In the combination of a stool having a substantially flat uppersurface and an ingot mold having a substantially fiat, open bottom whichis adapted to be rested upon the upper surface thereof, the improvementwhich x consists in the provision of a shallow recess in the upper;

surface of said' stool, which recess is of greater size along an axs inthe plane' thereof than the corresponding dimen-f sion of the said moldtaken along the same axis, butwhich recess is oflesser area than thearea of the inside' opening at the bottom of saidmold, and a smirchplate' asbestos in densely compacted relation, disposed within therecess, the said smirch plate having its upper surface substantiallyflush with the s'urface of said stool lying beyond the boundaries ofsaid recess, whereby the ingot mold may -be disposed in straddlngrelation to said recess and plate therein at opposedpoints thereof, andthereby fasten the smirch plate fi'rrnly in said recess.

3. A stool which is adapted to su port ingot molds of predetermined sizein the casting of ingots in said molds, the said stool having asubstantially fiat upper surface' and having a substantially rectangularrecess in its upper surface, the area of the said rectangle being lessthan the area of the inside opening' ofan ingot' mold'which is to bedisposed upon said stool, but the said recess being greater in one ofits coordinate dirensions than the corresponding dimension of the saidingot mold which is adapted to be rested upon said stool, whereby theingot mold may be positioned upon' said stool to straddle opposed areas'of said recess', and a smirch plate disposed within said recess' andhaving its upper surface substantially flush with the' upper surface' ofsaid stool in* areas lying' beyond the* said recess.

4. In the combination of a' stool having a substantially flat upper*surface and an ingot mold having a substantilly.flat,ropen bottom whichis' adapted to be' rested upon' the upper surface' thredf the"improvement which consists' in` the provsion of a shallow recess' inthe'uppersurface of said stool, which recess is" of greater size alongan-axs in` the plane therof than the correspondng inside dimension ofthesaid mold taken along the' same axis; but-which recess is of lesser areathan the area of the in'si'de opening at the' bottom of said mold, and asmirch plate disposed within` the recess; the said smirch plate havingits'u'pper surface substantially flush' with the surface of s'aid'stool'lying beyondthe boundaries' of'sid recess;` ;whereby the` ingotmold maybe disposed in straddling relation to said' recess and plate therein at'opposed points thereof and. thereby fastenthe smirch plate r'ml'y insaid recess.

References cited in the file of this patent UNITED STATES PATENTS

